EASILY DISCONNECTABLE HOIST RING ASSEMBLY
Swivel shackle assemblies have been used for many years in conjunction with cables and a hoist to lift and move heavy objects about the workplace, such as dies, molds, heavy castings, etc. These swivel shackle assemblies typically include a "U" shaped shackle member that is pivotal on a swivel body that in turn is rotatable about an axis on a base that is perpendicular to the swivel axis of the shackle on the base. This enables the shackle to accommodate two axes pivotal movement which is necessary for the geometry of the hoist arrangement.
In a typical hoist arrangement, an overhead crane has a depending single cable that is tied to four(more or less) outwardly extending cables connected to the shackle assemblies. Each shackle assembly typically has a threaded fastener extending centrally there-through that bolts the shackle directly to the top surface of the die or mold.
The following patents are representative of the prior art relating to dual axis hoist shackle assemblies.
The Andrewe, et al., U.S. Pat. No. 3,297,293, issued Jan. 10, 1967; the Tsui, et al., U.S. Pat. No. 4,705,422, issued Nov. 10, 1987; and the Chandler, U.S. Pat. No. 5,352,056, issued Oct. 4, 1994, all show swivel shackle assemblies having a "U" shaped member or shackle that is pinned to a rotary swivel member by transverse pins that are separate from the "U" member itself. In this design, it is necessary to fix these shackle pins in the swivel body.
A second group of patents represented by the Wong, et al., U.S. Pat. No. 4,570,987, issued Feb. 18, 1996; the Tsui, et al., U.S. Pat. No. 4,641,986, issued Feb. 10, 1987; and the Tsui, U.S. Pat. No. 5,405,210, issued Apr. 11, 1995, show hoist swivel shackle assemblies in which the ends of the "U" shaped shackle extend radially inwardly and form the pivotal bosses for the shackle on the swivel body member. This design somewhat reduces the long term loading problem on the shackle discussed above, but it does not significantly minimize that problem.
The Mueller, U.S. Pat. No. 3,492,033, discloses a clevis assembly with a locking ring 48 for locking the stud to the load. Mueller's clevis is not easily disassembled, however.
The Brawand, U.S. Pat. No. 3,163,901, shows a cargo hook and chain device in which a line holder 14 is detachable from member 10 and adapted to hold one or more load cables 16. The line holder 14 has an arcuate slot that permits its removal from a swivel-type draft line terminal member 10. There is no significant savings in the Brawand device because the line holding member 14 is a simple inexpensive loop-shape member.
The Blatt, U.S. Pat. No. 3,628,820, shows a side pull type swivel-type hoist ring assembly in which the hoist ring is generally perpendicular to the axis of the shoulder screw 28. Blatt's retaining ring 22 and block 12 are not readily removable from the screw 28.
The Bateman, U.S. Pat. No. 1,321,356, shows an anchor shank and shackle in which the shackle itself is removable from the anchor shank 9. However, the anchor shank 9 is not a swivel-type anchor shank and the removal of the shackle by itself results in no significant savings or benefits.
The Jergens Manufacturing Co. makes a line of side pull style hoist rings identified as part numbers 47311 to 47319 that have extra-large diameter rings and generally U-shaped swivel members. The swivel members, however, cannot be removed from the load without removing the anchor bushing itself.
In U.S. Ser. No. 09/072,823, a side pull hoist ring assembly is described for transporting loads including an anchor bushing that is threaded into the load and forms the pivot for a releasable hanger ring assembly with a shackle connectable to an overhead hoist. The hanger ring is quickly attachable and detachable from the anchor bushing to expedite load movement. The hanger ring swivels on the anchor bushing in a side pull action and has a key hole slot that hangs the anchor bushing during use and permits the hanger ring to be rapidly removed from the anchor bushing when the hoist is slacked by shifting a latch lever out of the way and lowering the swivel hanger to the large portion of the key hole slot that enables removal of the swivel hanger. The latch lever holds the hanger ring on the anchor bushing when the swivel hanger ring is unloaded.
It is a primary object of the present invention to ameliorate the problems noted above and provide side pull and center pull hoist ring assemblies with an easily removable swivel and shackle.